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Hello Harshvardhan,

Yes, I have tried changing PSDUNIT,1,PRESS to both PSDUNIT,1,ACEL and PSDUNIT,1,ACCG. Although it does not give me a calculation error, the results I get in the case of ACEL and ACCG. are equal to 0.

I have looked at the Solver Output and the fundamental difference is that for ACEL and ACCG there is no PARTICIPATION FACTORS FOR NODAL EXCITATION, while for PRES there is. (I leave images below).

I have also tried to put CMACEL in the modal, to be able to use the LVSCALE for acceleration. But it does not work either.

Below I leave the two commands. With "!" are the parts that I have used to try to insert the PSD as a g^2/Hz acceleration.

For the Modal:

sf,FACE3,press,1

!CMACEL,FACE3,1

For the Harmonic:

psdunit,1,pres

!psdunit,1,acel

!psdunit,1,accg

lvscale,100! scale pressure from modal

psdfrq,1,1,10,10000! create spectrum table using constant value / change as needed

psdval,1,10,10 ! create spectrum table using constant value / change as needed

pfact,1,node! nodal excitation

!dmprat,.01 ! damping ratio

!psdcom

!solve

Could you help me with that?

Regards